The invention relates to a diaphragm pump having several cylinders which are arranged in a row and which each form the stroke working space of a piston or plunger as well as having pump working spaces arranged in the same number which each may be closed off, on the suction side, by an inlet valve arrangement and, on the pressure side, by an outlet valve arrangement and are separated by a diaphragm from the stroke working space of the assigned piston or plunger, the work of the piston or plunger being transmissible to the diaphragm by a transmission fluid received in the stroke working space.
Diaphragm pumps of this type are known. In this case, the pump working spaces are each arranged as an extension of the working spaces so that a constructively simple design is obtained of the connecting paths from the stroke working spaces to the respectively assigned diaphragms of the pump working spaces. The driving mechanism of the pistons or plungers of these known diaphragm pumps, in principle, corresponds to the driving mechanism of conventional piston or plunger pumps which operate without any diaphragms and in which therefore the stroke working spaces at the same time form the pump working spaces. Also, the manufacturing expenditures for these known diaphragm pumps are undesirably high. This is mainly based on the fact that the stroke working spaces or pump working spaces, in the area of the diaphragms, generally have very large cross-sections which are significantly larger than the cross-sections of the pistons or plungers. Correspondingly, the pump working spaces can be arranged as an extension of the respectively assigned stroke working spaces only if the distances between the cylinders are correspondingly large and thus are dimensioned very differently from those of conventional piston or plunger pumps without diaphragms. The result is that, up to now, special driving mechanisms had to be built for the pistons or plungers for the diaphragm pumps of the initially mentioned type; i.e., the driving mechanisms of conventional piston or plunger pumps without diaphragms could not be used.
It is an object of the invention to provide a diaphragm pump which can be manufactured at a particularly low price.
In the case of the initially mentioned diaphragm pumps, this object is achieved according to preferred embodiments of the invention in that the cylinders are arranged at distances which are narrow in comparison to the cross-section of the pump working spaces, and the pump working spaces are arranged on different sides of the row of cylinders or of a cylinder block receiving the cylinders.
The invention is based on the general idea that the pump working spaces may be arranged in a varied manner relative to the stroke working spaces. In particular, in addition to arranging the pump working space as an extension of the stroke working space, an arrangement laterally next to the stroke working space is also possible. Because of the fact that the pump working space assigned to adjacent stroke working spaces are arranged on different sides of the row of cylinders or of the cylinder block, even, in the case of narrow distances of the cylinders, sufficient space is available for the arrangement of the diaphragms. Thus, the invention moves away from the traditional construction of diaphragm pumps in which the pump working spaces and the stroke working spaces which are assigned to one another are in each case arranged in the same manner relative to one another. Even though the different arrangement of the pump working spaces relative to the stroke working spaces provided according to the invention results in certain additional manufacturing expenditures, the manufacturing costs of the diaphragm pump according to the invention, as a whole, remain comparatively low because the piston or plunger driving mechanism and thus particularly also the crank mechanism may remain unchanged in comparison to conventional piston or plunger pumps without any diaphragm. Thus, to a large extent, the diaphragm pump according to the invention can be manufactured by using industrial-scale parts of conventional pumps.
In the case of a three-cylinder pump, the pump working space assigned to the center cylinder is preferably arranged as an extension of the center cylinder, and the pump working spaces assigned to the other cylinders are preferably each arranged laterally of the cylinder axis, these two latter pump working spaces expediently each being situated as an extension of the row of cylinders.
This arrangement is possible in the same manner in the case of pumps with vertical cylinders as well as in the case of pumps with horizontally arranged cylinders.
Another advantage of the invention is the fact that basically diaphragms of any shape may be used; i.e., the invention is not limited to diaphragm pumps with a special diaphragm shape. For example, according to the invention diaphragm pumps are conceivable which have tubular diaphragms as well as those which have flat diaphrams.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.